550555561 has 8 divisors (see below), whose sum is σ = 567251144. Its totient is φ = 534107520.

The previous prime is 550555547. The next prime is 550555613. The reversal of 550555561 is 165555055.

It can be written as a sum of positive squares in 4 ways, for example, as 10272025 + 540283536 = 3205^2 + 23244^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 550555561 - 2⁷ = 550555433 is a prime.

It is a super-2 number, since 2×550555561² = 606222851496049442, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 550555561.

It is not an unprimeable number, because it can be changed into a prime (550555501) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 57366 + ... + 66271.

It is an arithmetic number, because the mean of its divisors is an integer number (70906393).

Almost surely, 2^550555561 is an apocalyptic number.

It is an amenable number.

550555561 is a deficient number, since it is larger than the sum of its proper divisors (16695583).

550555561 is a wasteful number, since it uses less digits than its factorization.

550555561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 123771.

The product of its (nonzero) digits is 93750, while the sum is 37.

The square root of 550555561 is about 23463.9204098548. The cubic root of 550555561 is about 819.5970462180.

The spelling of 550555561 in words is "five hundred fifty million, five hundred fifty-five thousand, five hundred sixty-one".